Abstract: A method of manufacturing an electronic component having a concave portion. A ceramic laminate is prepared having a plurality of sheets with burnaway film formed thereon. The burnaway film material is capable of being burned away by firing. The burnaway film is provided in layers in positions corresponding to the desired position of the concave portion. Firing the ceramic laminate burns out the burnaway film, and a sintered body is formed with a plurality of cavities provided in layers between a plurality of thin laminate layers. Crushing the thin layers of the sintered body forms the concave portion.

Abstract: In order to obtain a stator of a variable capacitor, prepared is a ceramic laminate having a stator electrode provided in its interior and a plurality of burnaway films of carbon or resin, which can be burned away by firing, provided in positions corresponding to that of a concave portion in the form of layers. This ceramic laminate is fired to burn out the burnaway films thereby obtaining a sintered body provided with a plurality of cavities and a plurality of thin layers, and this sintered body is barrel-polished to crush the thin layers, thereby forming a concave portion. A rotor of a metal forming a rotor electrode is arranged on the stator obtained in the aforementioned manner. A cover of a metal is fixed to the stator through an engaging member engaging in the concave portion of the stator, to rotatably store the rotor while pressing the rotor against the stator by a spring action part.

Abstract: In a trimmer capacitor comprising a stator having a stator electrode, a rotor having a rotor electrode and a shaft holding the rotor in a rotatable manner with respect to the stator, the stator is formed of resin containing a dielectric ceramic material. The stator electrode is located in the interior of the stator, so that the stator electrode is opposed to the rotor electrode through a dielectric layer which is defined by an integral part of the stator. The stator, the stator electrode and the dielectric member which are required for the trimmer capacitor are entirely integrated with each other in the stator, whereby the trimmer capacitor can be easily assembled. The resin, containing the dielectric ceramic material, forming the dielectric layer is superior in shock resistance to a ceramic material, whereby no problem of cracking etc. occurs even if the thickness of the dielectric layer is reduced.